React learning #6 to Do List ,map
const food =[1,2,3,4] [5,food]// [5,Array[5]] 배열 안에 숫자와 배열이 들어감 [5,..food]//[5,1,2,3,4] 배열 안의 elements가 들어감 setTodos((currentTodo)=>[Todo, ...currentTodo]) function App() { const [toDo, setToDo] = useState(""); const [toDos, setToDos] = useState([]); const onChange = (event) => setToDo(event.target.value); const onSubmit = (event) => { event.preventDefault(); if (toDo === "") { return; //to Do가 ..